A fuel injector is used in an internal combustion engine, such as a compression ignition engine, to deliver or inject pressurized combustible fuel to a combustion chamber of the engine. Typically, fuel injectors include a fuel injector body and a valve, sometimes called a check, a check valve, a needle, or a needle valve, which can be movably disposed in the fuel injector body. The valve and fuel injector body may form a converging space at a discharging end of the fuel injector body, generally referred to as nozzle. In a closed position, the needle valve seals against the nozzle to prevent pressurized injection of combustible fuel from the nozzle of the fuel injector body. Conversely, in an open position, the valve can be lifted to inject the pressurized combustible fuel from the nozzle.
For some fuel injectors where the valve lifts to start injection and closes to stop injection, undesirable pulse injection control may result, for instance, with respect to pulse shape, duration and interval. Also, for some fuel injectors residual fuel in a volume between the valve and nozzle can create inconsistencies in the volume of fuel output by the nozzle.
U.S. Pat. No. 6,467,702, hereinafter referred to as '702 patent, describes a fuel injector, for instance, with reference to FIGS. 13-16, whereby a valve needle may be lifted from a state where fuel injection does not occur through either first outlet openings or second outlet openings to a second fuel injecting position where fuel injection occurs through only the second outlet openings. According to the '702 patent, from the second fuel injecting position the valve needle may be either returned to the state where fuel injection does not occur through either first outlet openings or second outlet openings or further lifted to a first fuel injecting position where fuel injection occurs through only the first outlet openings.